Electrolytic apparatus.



No. 697,|5`7. Patented Apr. 8, |902. F. McDONALD. ELECTRULYTIC APPARATUS.

(Application filed May 20. 1901.) (No Model.)

2 Sheets-$heet l.

No. 697,|57. Patented Apr. 8, |902.

F., MGIJONALD.

ELECTHOLYTIC APPARATUS.

(Application filed May 20. 1901,)

(No Model.) 2 Shee1s-Shee 2.

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UNrrnn STATES PATENT OFFICE.

FRANK MCDONALD, OF RUMFORD FALLS, MAINE.

ELECTROLYTIC APPARATUS.

SPECIFICATION forming part of Letters Patent No. 697,157, dated April. S, 1902.

Application led May 20, 1901. Serial No. 61,116. (No model.)

To all whom, it may concern.-

Be it known that I, FRANK MoDoNALD, a subject of the King of Great Britain, residing at Rumford Falls, in the county of Oxford and State of Maine, have invented certain new and useful Improvements in Electrolytic Apparatus; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to certain new and useful improvements in electrolytic apparatus designed for the electrolysis of metallic salts, the main object of the invention being to provide an apparatus so constructed as to effect a complete separation of the products of electrolysis. Y

Vith this and other objects in View, which will appear as the nature of the improvements is better understood, the invention consists of certain novel features of construction, combination, and arrangement of parts, as will be hereinafter more fully described, and particularly set forth in the appended claims.

In the accompanying drawings, Figure l is a side elevation of an electrolytic apparatus embodying myinvention. Fig. 2 is a top plan view of the same. Fig. 3 is a vertical longitudinal section through the anode-chamber. Fi g4 is a vertical lon git udinal section through one of the cathode-chambers. Fig. 5 is a cross-section through the apparatus, and Fig. 6 is a detail sectional view of one of the electrodes.

In describing my invention I will refer to it as applied and constructed for the electrolysis of sodium chlorid in the form of an aqueous solution or brine.

Referring now more particularly to the drawings, the numeral l represents the electrolytic tank, which is preferably of oblong rectangular form and made of iron, but may be made of any other suitable form and material. Extending longitudinally Within the tank are perforated iron or other metallic plates 2, flanged at suitable points for attachment to the walls of the tank and subdividin g the interior of the tank to form the central anode-compartment 3 and cathode-compartments 4. Any number of these plates may be employed, according to the number of anode and cathode chambers to be used.

The inner face or side of each plate 2 is lined with a layer 6 of asbestos cloth and a layer 7 of asbestos paper, and the joints or spaces between the same and the bottom and end walls of the tank are sealed by a coating or lining 8 of cement, which holds the asbestos cloth and paper in position and also protects the metallic tank from the action of the solution contained Within the anode-compartment. The inner faces of the end walls of the anode-compartment are recessed for the reception of the cement and also for the reception of the ends of the hanged-rim cover 9, which closes the top of the anode-compartment. This cover fits down between the upper edges 10 of the plates 2, which are curved outwardly to form a seat for the reception of a layer of cement 11, which extends completely around the cover and hermetically seals the joints between the same, the end walls of the tank, and the plates 2 and prevents the escape except through the proper channel of the gases from the anode-compartment. The cover 9 may be constructed of glass, porcelain, or any other suitable material capable of resisting acids. The layers 6 and '7 of the abestos cloth and paper form diaphragms between the anode and cathode compartments.

The top of the cover 9 is formed with openings for the passage of electrodes, each consisting of a tube or cup 12, of glass or other suitable insulating material, between which and the wall of the opening an air-tight fillingof cement is placed. The positive wires 13 are tted in these cups and contact with mercury 14c placed therein, and also in electrical connection with the mercury and extending down into the anode-compartment are thin thread or ribbon like filaments or strips 14' of platinum foil, which are sealed into the cup. These strips project some distance down into the tank in close proximity to the asbestos diaphragms, and by their use a much more thorough and eeotive distribution of the electric current through the solution in the anode-compartment is effected than it is possible to attain by the use of platinum wire. In a full-sized apparatus employing a tank about five feet in length by one foot in width and depth these strips will preferably be about ten inches long and two inches wide; but the proportions may be varied to some extent, if desired. Each cathodecompartment is tightly closed by means of an acid-proof cover 15, and the negative wires'` ing with the cathode-compartments for carrying 0E the caustic liquid. These pipes are of elbow form and so arranged as to cause the withdrawal of the caustic liquid from the bottom of the cathode-compartment, thus preventing the escape therethrough of the hydrogen gas.

The brine is supplied to the anode-compartment from a suitable source of supply by means of a pipe 20, and its feed is controlled by an automatic feeder consisting of a vessel 21, in communication by a tube 22 with the anode-compartment, so that the level of the liquid in said Acompartment and vessel will alwaysremain the same. A iioat 23 is contained in the vessel 21 and is connected by a rod 22 with avalve 23 in the pipe 20, whereby the rise and fall of the liquid in the anodecompartmentcontrols the supply of the fresh liquid through the pipe 2O thereto.

In operation the compartments are filled with brine,and the current is then turned on. Thechlorin gas being an electronegative element goes -to the positive pole and appears at the anode-compartment, while the sodium being electropositive goes to the negative pole or the cathode-compartment, where it acts on the water and forms caustic soda (NaGH) according'to the following reaction:

as will be readily understood by those conversant with the art.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In an electrolytic apparatus, the combination of a metallic tank, spaced perforated metallic plates electrically connected with the tank and subdividing the tank to form anode and cathode compartments, asbestos diaphragms lining said plates, a layer of acidproof cement covering the inner surface of the bottom and end walls of the tank between the diaphragms, a cover hermetically sealing the anode-compartment, a cover sealing the to form anode and cathode compartments andhaving their upper edges outwardly curved to form seats cooperating with said recesses,

, asbestos diaphragms lining the perforated plates,a coverin the anode-compartment supported by said plates and fitting down in the seat formed by said outwardly-curved edges of the plates and the recessed end walls of the tank, a filling of cement hermetically sealing said seat around the cover, positive electrodes carried by said cover, negative connections to the plate and tank and a cover sealing the cathode -compartment, substantially as described.

3. In an electrolytic apparatus, the combination of a tank,spaced perforated plates subdividing the interior of the tank into anode and cathode compartments, the end walls of the tank being recessed and the upper edges of the plates outwardly curved to form a groove or seat, asbestos diaphragms lining the perforated plates, a cover closing the anodecompartment and resting upon said plates within said seat, sealing material inserted within the seat around the cover and hermetically closing the joints between said cover and plates and the end walls of the tank, positi've electrodes carried `by said cover, negative connections to the plate and tank, a second cover closing the cathode-compartments, a layer of acid-proof cement lining the bottom and end walls of the tank and covering the space between the edges of the asbestos diaphragm, chlorin'and hydrogen pipes connected, respectively, with the anode and cathode compartments, overflow-pipes connected with the cathode compartments, a feed-pipe connected with the anode-compart ment, a gage also connected with said cornpartment for indicating the level of the fluid therein, a valve in the feed-pipe, a vessel communicating with the anode-compartment and a float in said vessel and connected with said valve, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subseribingwitnesses.

FRANK MODONALD.

Witnesses:

ARETAs E. STEARNS, 'OLIVER L. BLANCHARD.

IOC

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